Due to developing technology, horizontal wells are now being used both as producing wells and injection wells in the petroleum industry. Although selective perforation and stimulation activities are now able to be carried out in cased horizontal wells as well as in vertical wells, difficulties have been encountered in moving tubing strings and related equipment through the high angle and horizontal sections of the wells. As they traverse these sections, the tubing string and the completion equipment carried by the tubing string tend to slide along the bottom of the wellbore. This causes the operators to have a loss of "feel" to the tubing and tools, which is detrimental to accurately moving and positioning the tools in the desired area. It can also result in damage to the tubing string or equipment, requiring the tubing string to be withdrawn and the damaged portions of the tubing and equipment replaced.
In addition, difficulties have been encountered in properly placing and preventing damage to equipment used in multiple zone completion activities in horizontal injection wells.
It would be highly desirable to be able to carry out completion activities in horizontal wells without encountering problems caused by the traversing of tubing strings through high angle and horizontal sections of the wellbores.